1. Field
Aspects of embodiments relate to a battery management system and a switching method thereof.
2. Description of the Related Art
Vehicles using the internal combustion engine using gasoline or diesel oil as vehicle fuel release harmful exhaust gases considered to be one of the primary causes of air pollution. Accordingly, in recent years, in order to decrease environmental pollution, efforts to develop electric vehicles and hybrid vehicles have been actively pursued.
An electric vehicle has an electric motor that is powered by a battery pack including a plurality of rechargeable secondary battery cells. Since an electric vehicle uses a battery pack as a main power source, exhaust gas is not generated and little noise is produced. A hybrid vehicle combines elements of an internal combustion engine vehicle and of an electric vehicle, using, for example, both an internal combustion engine and a battery-powered motor.
In a vehicle using electrical energy, battery performance directly affects the performance of the vehicle. Thus, each battery cell should have excellent performance, and there is a need for a battery management system capable of efficiently managing charge and discharge of each battery cell by measuring the voltages of individual battery cells, and the voltage, current and temperature of the entire battery pack.
The battery management system may include a plurality of relays for supplying power from a battery to a motor, supplying power from a generator to a battery, or blocking a power supply in an emergency. A relay may be subjected to severe stress if it is turned off (opened) while current is flowing through it; in particular, it may be melted as arcing and voltage spikes occur in the relay.